I had that same issue too. I reordered the transcripts during my application but that's probably out of fear than necessity. However, I recall something like, if the schools already have your profile, meaning you've started your application before writing the DAT, then you're good otherwise you'll have to resend your scores. If someone can double check for me that'd be great.

From last year's application I just listed all the things I've done and the dates. It's all inputted into their online application. It'll be arranged according to date. It's best to not have large gaps between activities from my guess.

I'm going to cast my vote for developmental biology and biochemistry. From what I can remember, just the Kaplan book was good enough for ecology and evolution. Also, biochemistry is good for that 1.0 credit that schools are looking for.

Kinda hard to say about your chances. To me it seems borderline as an undergrad student. GPA is okay DAT is okay. Nothing seems "stellar" about either one. If your DAT is amazing or GPA is amazing or both then I could say you have a decent shot, but right now not really. If, however, you did a Masters then you would have a decent shot but that would mean spending an extra 2 years.
Also English was a nightmare for me. I took it in 4th year and ended with a 66%. RIP.
But anyway don't take my word 100% I could very well be wrong. It's just my own speculation.

I used only the Kaplan DAT book and it basically worked well for me. PAT section was a bit on the "easy" side compared to the actual exam especially the angles section. The same for RC. The sciences were good.

Just nail the DAT and you should be pretty good. I had 3.73 GPA (plus a Master's). I volunteer at a hospital and I also work at Kumon (funnily enough). Now I'm accepted and going to UofT (UofT peeps like graduate students from what I've heard).

Cell bio counted toward USask's requirement but not UBC's
At first USask said I was missing my biochem requirement, but I emailed them and they said it was their mistake and cell bio counted.
Sources: Myself from my 2018 application.

I could very well be an exception at UofT, but I had a 3.73 GPA and did a thesis based Masters with 26AA and 21PAT. I don't think my ECs were outstanding in any way as well. I ended up getting an interview and eventually an acceptance.
I think you totally have a shot!

I believe that should fulfill the requirement.
"Students registering in 1st year are required to obtain certification of satisfactory completion of (a) a Canadian Red Cross Society or St. John's Ambulance course in First Aid (or its equivalent) and (b) a CPR Basic Rescuer course before they may register in first year of the D.D.S. pro­gram."
Standard first aid should fulfill part A and CPR-C should fulfill part B.